The present invention relates to the field of drainage systems; more specifically, it relates to a subterranean drainage system for structures, which are buried wholly or partially beneath the surface of the earth.
Proper drainage is an important consideration in the design and construction of subterranean structures that may be partially or completely buried. Such subterranean structures include walls and footings that may be formed from poured concrete, cement blocks or other materials. Without proper drainage, hydrostatic pressure can result in structural damage and leakage into the interior of the structure.
Conventional drainage systems have used perforated pipe laid in a gravel bed along a side of the structure. However, because the pipe-in-gravel system still allows water to contact the structure above the gravel bed, this system is not always successful in protecting the structure. A development in this area is dimpled drain boards comprising a series of raised dimples that provide structural integrity to the board while allowing water to flow between the dimples when the board is laid vertically or horizontally. Because the board may be wide, more of the structure may be covered. To prevent earth and other materials from clogging the space between the hollow dimples, a water permeable mat is placed over the dimples.
However, several problems exist with current dimple board drainage systems. For example, the volume of water that may be drained is fixed and limited by the geometry of the hollow dimple board, and in large area installations, water may back up as the bottom of the drainage system fills. Further, assembly of boards and attachment of outlets can require the use of large numbers of fasteners increasing the time and labor required for installation of the system, especially in large and complex structures.
Therefore, there is a need for a drainage system that is field adjustable in terms of the quantity of water it can handle and that minimizes the need for fasteners.
A first aspect of the present invention is a dimpled drain board comprising: a planar base; a hollow dimple extending perpendicularly from the planar base; and a connector, the connector adapted to maintain the planar base in a spaced apart relationship from another planar base of another dimpled drain board having another hollow dimple.
A second aspect of the present invention is a dimpled drain board comprising:
a planar base having a first surface and a second surface;
a multiplicity of hollow dimples arranged in a repeating pattern and extending perpendicularly from said planar base, each hollow dimple having a sidewall, a closed top and a bottom open to said second surface; and a connector operatively associated with all or less than all said hollow dimples, each connector adapted to maintain said planar base and another planar base of another dimpled drain board in a spaced apart relationship.
A third aspect of the present invention is a drainage system comprising: at least two dimpled drain boards, each dimpled drain board including: a planar base having a first surface and second surface; a multiplicity of hollow dimples arranged in a repeating pattern and extending perpendicularly from said first surface of said base, each hollow dimple having a sidewall, a closed top and a bottom open to said second surface; and a connector on all or less than all said hollow dimples, each connector adapted to maintain said planar base of said dimpled drain board and another planar base of another dimpled drain board in a spaced apart relationship, said another dimpled drain board having other hollow dimples identical to said hollow dimples of said dimpled drain board; and filter means arranged to prevent non-fluid materials from depositing between said hollow dimples.
A fourth aspect of the present invention is a drainage system comprising: a dimpled drain board comprising a planar base having a first surface and second surface and a multiplicity of hollow dimples arranged in a repeating pattern extending perpendicularly from said first surface of said base, each hollow dimple having a sidewall, a closed top and a bottom open to said second surface; and a connector operatively engaged to one or more of said hollow dimples of said dimpled drain board.